Truss elevating device (hydraulic popup device)



R. E. HEISE L Nov. 10, 1970 TRUSS ELEVATING DEVICE (HYDRAULIC POPUPDEVICE) Filed May 29, 1968 3 Sheets-Sheet 1 mm Fm INVENTORS fi/CHARD E.IVE/5E ADOLFO CAST/LL 0 TRUSS ELEVATING DEVICE (HYDRAULIC POPUP DEVICE)Filed May 29, 1968 NOV. 10, 1970 5, 555 ETAL 3 'ShetsSheet a vw M TRUSSELEVATING DEVICE (HYDRAULIC POPUP DEVICE) Filed May 29, 1968 R. E. HEISENov. 10, 1970 3 Sheets-Sheet 5 3,538,578 TRUSS ELEVATHNG DEVICE(HYDRAULIC POPUP DEVICE) Richard E. Heise and Adolfo Castillo, Miami,Fla, as-

signors to Automated Building Components, Inc., Miami, Fla., acorporation of Florida Filed May 2% 1968, Ser. No. 733,104 Int. Cl. B23p19/00 US. Cl. 29200 14 Claims ABSTRACT OF THE DISCLOSURE The presentdevice includes a conveyor operable to advance a jig table carrying thewooden elements forming a truss through a press. The spaced joints ofthe truss are successively located below a press platen whereat nailplates of the type having a plurality of teeth struck therefrom areembedded into the joints. A fluid actuated slave cylinder is locatedadjacent the leading heel reaction pad of the jig table and is operablyconnected to a pivoted member located below the leading heel joint ofthe truss whereby actuation of the slave cylinder pivots the memberupwardly to elevate the leading portion of the truss from the jig table.A master cylinder is mounted on the jig table behind and connected tothe slave cylinder via a fluid line. The master cylinder carries alinkage projecting above the truss elements whereby the linkage actuatesthe master cylinder in response to downward movement of the press platento provide fluid to the slave cylinder, thereby elevating the leadingheel portion of the completed truss above the jig table onto anautomated truss unloading mechanism.

BACKGROUND AND SUMMARY OF THE PRESENT INVENTION The present inventionrelates to automatic machinery for producing wooden structural elementsand more particularly to apparatus which aids in the unloading ofcompleted wooden structures, such as roof trusses, from the automaticmachinery by which the structures are produced.

Recently, the wooden building construction industry has shown a markedtrend toward prefabrication of wooden structural components,particularly in the construction of relatively low cost housing. Themost common prefabricated element of the various portions of houseswhich have been preassembled in this fashion is probably the monoplaneroof truss.

Concurrently with this development, prefabrication techniques andpractices in forming prefabricated wooden structures, such as rooftrusses, have evolved from joint formation by hand nailing and boltingtechniques to the improved and far superior mode of construction whichwas made possible by the advent of structural butt joints employingunitary connector plates of the 7 type described in US. Pat. No.2,877,520 of common ownership herewith. A current method of producingprefabricated roof trusses employing the joint construction of theforegoing patent employs a jig assembly, an example of which isdisclosed in US. Pat. No. 3,241,585 of common ownership herewith. Thesedevelopments have made it possible to manufacture trusses of varioussizes and shapes with a minimum of skilled labor and at substantiallyreduced cost. However, since completed trusses are of substantialweight, bulky and somewhat awkward to remove from the jig assembly, ithas been a problem to ofiload the trusses from the jig assemblies with aminimum of labor onto appropriate storage or transporatation facilities.

Automated truss unloading and stacking devices have States Patent beenprovided in the past for removing the completed truss from the jigassembly and positioning it in an upright position for subsequenthandling. An example of such devices is disclosed in copendingapplication Ser. No. 578,365, filed Sept. 9, 1966, now Pat. No.3,389,812, of common ownership herewith. Such devices are located at theoutput side of a press and automatically remove the truss from the jigby virtually peeling the completed truss from the jig assembly.Elevation of the leading portion of the truss is, however, necessary toinitially locate the truss in an ofiioading position relative to theunloading and stacking devices.

According to the present invention, it has been found that the truss canbe automatically elevated from the jig assembly prior to its engagementon the unloading device by an assembly carried by the jig table.Moreover, the leading heel portion of the completed truss can beelevated from the jig table to an unloading position at the exit end ofthe press while the remaining portions of the uncompleted truss arebeing subjected to the press operation thus affording a savings in timeand space. The foregoing is accomplished by a unique arrangement andmode of actuation of fluid actuated master and slave cylinders carriedon the jig table. The leading heel pad on the jig table includes amember underlying the heel portion of the truss which member can bepivoted upwardly to elevate the completed leading heel portion of thetruss from the jig table. A slave cylinder is connected to the pivotedmember to effect the pivoting action thereof. A master cylinder iscarried on the jig table rearwardly of the heel pad and is connected tothe slave cylinder through a fluid line. A linkage connected to themaster cylinder projects above both the jig table and the truss elementslying on the jig table. The press platen engages the linkage on itsdownward stroke when the nail plates of a succeeding joint are embedded,thereby actuating the master cylinder. Actuation of the master cylinderprovides fluid to the slave cylinder which then pivots the hinged memberupwardly thereby elevating the completed heel portion of the truss abovethe jig table surmounting the unloading device as the jig table emergesfurther from the press.

It is accordingly a primary object of the present invention to providean improved unloading device for use with apparatus for manufacturingwooden structures.

It is another object of the present invention to provide an improvedtruss unloading apparatus including a truss elevating device which isautomatically operable to elevate one end of the completed truss from ajig table.

It is still another object of the present invention to provide animproved truss unloading arrangement including a truss elevating devicewhich is automatically reset for reuse.

It is a further object of the present invention to provide a trussunloading apparatus including a fluid actuated truss elevating devicecarried on the jig table and with minimum modification of the jig table.

It is still a further object of the present invention to provide a trussunloading apparatus for elevating one end of the completed truss inresponse to actuation of a truss fabricating press operating onremaining portions of the truss.

It is a related object of this invention to provide a truss unloadingdevice which is automatic and simple in operation, economical tomanufacture, readily and easily installed on existing jig tables, anddoes not require separate power sources.

These and further objects and advantages of the present invention willbecome more apparent upon reference to the following specification,claims and appended drawings.

3 DESCRIPTION OF THE DRAWING FIGURES FIG. 1 is a fragmentary perspectiveview illustrating automatic machinery for fabricating trusses and showsthe leading end of a truss elevated onto an unloading roller assembly byapparatus constructed in accordance with the present invention;

FIG. 2 is a fragmentary side elevational view of the truss elevatingapparatus hereof;

FIG. 3 is a fragmentary side elevational view illustrating the leadingend of a truss elevated onto a truss unloading apparatus by theelevating apparatus hereof;

FIG. 4 is a fragmentary plan view of the truss elevating apparatushereof;

FIG. 5 is an enlarged plan view of the actuating assembly for the trusselevating device hereof with parts broken away for ease of illustration;

FIG. 6 is a cross sectional view thereof taken about on line 66 of FIG.5;

FIG. 7 is a fragmentary end elevational view thereof taken about on line77 of FIG. 4;

FIG. 8 is a fragmentary exploded perspective view of a hinged elevatingassembly;

FIG. 9 is a plan view of the elevating assembly with parts broken awayfor ease of illustration; and

FIG. 10 is a side elevational view thereof illustrating the normal andtruss raising positions of the truss elevating device hereof.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to the drawings and moreparticularly to FIG. 1, there is shown an automatic system lit forfabricating wooden structures, such as trusses. System 10 includes aconveyor, generally indicated at 12, on which jig assemblies 14 arecarried. Conveyor 12 extends through a press 16 which may be of the typeshown, for example, in assignees US. Pat. No. 3,195,449. Press 16 isoperative to press unitany connector plates 18 of the type illustrated,for example, in assignees US. Pat. No. 2,877,523, into the structuralbutt joints as the latter are successively located below press 16 withjig assembly 14 being advanced along conveyor 12 from top to bottom asseen in FIG. 1. As will become clear, the apparatus of the presentinvention is effective to elevate the leading end of a completed truss20 as it passes through the press and emerges therefrom on a trussunloading roller assembly, generally indicated at 22.

Unloading roller assembly 22 comprises longitudinally spacedtransversely extending rollers 24 and 26 supported at the unloading sideof system 10 in spaced relation above conveyor 12. Rollers 24 and 26 aresupported above conveyor 12 such that truss 20 may be lifted from jigassembly 14 as the jig assembly is continuously advanced along conveyor12. The opposite ends of rollers 24 and 26 are mounted in rollerbearings 28 carried on stands 29 on opposite sides of conveyor 12. Asseen more clearly in FIG. 3, a scoop plate 30, of generally triangularcross sectional configuration, is carried by stand 29 ahead of rollers24 to guide truss 20 onto rollers 24 and 26.

The chords and web members which are joined together by the embedment ofplates 18 at the joints thereof by press 16 to form a completed trussare manually positioned on jig assembly 14 and on opposite sides of thejoints. Only the more significant details of jig assembly 14, which willbe useful to bring out the environment of the present invention, areillustrated and reference is made to assignees US. Pat. No. 3,241,585for a more detailed description of the jig assembly and the workingrelationship of the elements thereof.

Briefly, jig assembly 14, seen in FIG. 1, is shown to be preset forproduction of a gable-type truss consisting of one or more bottom chords30, top chords 32, and web members 34. Jig assembly 14 comprises a jigtable, preferably formed of heavy sheet metal, upon which the jigelements are mounted. A first pair of longitudinally extendingstationary guide bars 38 and 40 are shown adjacent opposite sides of jigtable 36 and a plurality of transversely extending guide bars 42 arelongitudinally spaced along table 36. Bars 42 are provided with suitableconnectors 44 at opposite ends which are slidable along longitudinallyextending guide bars 38 and 40 whereby bars 42 may be selectivelypositioned along table 36. Reaction pad assemblies 46 are slidablymounted on transversely extending guide bars 42 whereby pads 46 may beselectively positioned transversely along jig table 36 below the buttjoints formed by top chords 32 and webs 34.

Additional reaction pad assemblies 48 are selectively positioned alongguide bars 38 below the butt joints formed by the ends of bottom chords30 and the lower ends of upper chords 32. The arrangement and functionof the reaction pads and guide bars are explained in detail in theaforementioned US. Pat. No. 3,241,584, it being sufiicient for presentpurposes to refer only to the leading heel reaction pad assembly 50,i.e., the reaction pad which first enters into and emerges from press 16and from which the heel portion of the truss will be initially elevatedfrom jig table 36.

For background purposes, the jig is utilized by spotting connectorplates 18 on each of the reaction pad assemblies with the teethextending upwardly. The wooden chords and webs are then placed on top ofthe teeth and a second set of such connector plates are laid on top ofthe wooden chords and webs with their teeth directed downwardly, thereaction pad assemblies being located and providing releasable clampingdevices for clamping the various members of the wooden structure inplace to form a gable-type truss configuration. The jig table is thenadvanced through press 16 with the press being actuated when each of thebutt joints underlies upper press platen 52 to simultaneously press thetop and bottom connector plates 18 into the joints formed by theassociated wooden members. As the truss structure emerges from press 16,it continues to lie on the reaction pad assembly and, smce unloadingrollers 24 and 26 are vertically spaced above the truss, table, andconveyor, the truss must be elevated from the jig table for positioningon unloading assembly 22. More particularly, the leading end of thetruss is first elevated as to overlie scoop plate 30 and front roller 24by the apparatus of the present invention with the remaining trussportions being progressively peeled from the reaction pad assemblies asthe truss table and truss emerges from press 16 and are continuouslyadvanced along conveyor 12.

Generally, the truss elevating apparatus hereof comprises a trusselevating control assembly, generally indicated at 53, and an elevatingassembly, generally indicated at 54, responsive to actuation of controlassembly 53 to elevate the leading end of the truss from the jig table36 onto unloading assembly 22. The control assembly 53 includes a mastercylinder which is actuated in response to downward movement of pressplaten 52 to actuate a slave cylinder carried by elevating assembly 54which, in turn, pivots a member carried by heel reaction pad andunderlying the leading end of the truss to raise the truss from heelreaction pad 50.

More particularly, the elevating control assembly 53 comprises a baseplate 56 having an upright flange 58 extending along one side thereofand mounting a pair of laterally spaced upstanding brackets 60 and 62adjacent its opposite ends. A master cylinder 64 is pivotally mounted atone end to brackets 60 as by pin 66. Note that an elongated opening 67is formed through base plate plate 56 and receives a body portion ofcylinder 64 such that the vertical extent of plate 56 and cylinder 64 islimited for reasons as will become apparent. A piston rod 68 is carriedby cylinder 64 and is biased outwardly by a spring 69. Piston rod 68mounts a clevis 70 on its outer end to which the lower ends of a pair oflinks 72 and a roller 74 are connected as by a pin 76. The ends of links72 lie on the opposite sides of clevis 70 with roller 74 lying betweenthe legs of the clevis. The opposite ends of links 72 are pivotallyconnected to the upper end of link 78 as by a pin 80. A slot 82 isformed in the upper end of link 78 and a roller 84 is pivotally carriedby pin 80 within slot 82. The lower end of link 78 is pivotally con.-nected between brackets 62 as by a pin 86. The links 72 and 78 areformed such that roller 84 is normally spaced above the upper edge offlange 58 and cylinder 64 when piston rod 68 is fully extended under thebias of spring 69. In this manner, a downward force applied to roller 84extends linkage 72 and 78 to the dashed line configuration in FIG. 6 todrive piston rod 68 toward a retracted position within cylinder 64against the bias of spring 69 with roller 74 rolling along the upperface of base plate 56. Thus, fluid, preferably hydraulic fluid, will beforced from cylinder 64 through a nipple 88 and into a fluid line 90.When the force applied to roller 84 is removed, piston rod 68 willextend under the bias of spring 69 to relocate roller 84 in the normalvertically spaced position above the control assembly. That is, thelinkage 72 and 78 and roller 84 move from the dashed line configurationto the full line configuration in FIG. 6.

For reasons described hereinafter, the elevating control assembly 53 ismounted on jig table 36 for selected longitudinal movement therealong.To this end, a longitudinally extending guide bearing member 91 issuitably secured to jig table 36 adjacent a lateral edge thereof andspaced outwardly of guide bar 38. A bracket 92, secured as by welding tobase plate 56, projects laterally outwardly thereof to overlie bearingmember 91 and carries a lug 94 on its underside adjacent its outer end.Bracket 92 is suitably apertured as at 96 and a locking screw 98 extendsthrough aperture 96 in threaded engagement with a locking bar 100.Bearing member 91 and locking bar 100 have cooperating flanges i101 and102, respectively, whereby threading and unthreading of screw 98releasably clamps control assembly 53 in longitudinally adjustedposition to and along bearing member 91.

Referring now to FIGS. 8-10, there is shown the elevating assembly 54which comprises a hinged subassembly including a lever 103 hinged to therear edge of heel reaction pad 50 as by an elongated pin 104. The hingedsubassembly also includes a bar 106 suitably secured along the outerlateral edge of lever 103 and a roller surface or dowel 108 secured asby welding to the opposite free edge of lever 103. A bracket flat 110 issuitably secured to heel reaction pad 50 adjacent its forward lateraledge and a bracket 112 carrying a pair of upstanding flats 114 issuitably secured to flat 110 as by bolts 116. A fluid actuated slavecylinder 118 is pivotally mounted at one end to flats 114 as by a pin120.'A piston rod 122 is biased outwardly by a pin 124 and mounts aclevis 126 which is pivotally secured to a lever arm 128 as by a pin130. Lever arm 128 is suitably hinged about pin 104 which projectsbeyond the lateral edge of heel pad 50. A hinge outboard bearing 132 issecured to the lateral edge of pad 50 adjacent its trailing end toreceive the outer end of pin 104 and prevent lateral axial displacementof lever arm 128 along pin 104. As seen in FIG. 10, lever arm 128underlies arm 106 such that clockwise pivoting of lever 128 about pin104 pivots lever 103 in a like clockwise direction about pin 1104. Withlever 103 positioned adjacent the trailing edge of heel pad 50, itunderlies the leading heel portion of the truss and it will be seen thatretraction of piston rod 122. against the bias of spring 124 pivotslever arm 128 and lever 103 about pin 104 causing the heel portion ofthe truss to be elevated from heel reaction pad 50. Fluid line 90 issuitably connected to cylinder 118 to supply fluid thereto to retractpiston rod 122 against the bias of spring .124. It will be noted thatthe clamps carried by the reaction pads to retain the chords and webs ofthe truss in place before table 36 passes through press 16 areautomatically released as by opera tion of press platen 52 as noted inassignees US. Pat. No.

3,238,867 and thereby the completed truss is free for elevatingmovement.

To manufacture a truss and position the same on unloading assembly 22 inaccordance with the present invention, reaction pads 46 are selectivelypositioned along guide bars 42 with guide bars 42 being selectivelypositioned along guide bars 38 and 40. Reaction pads 48 are selectivelylongitudinally positioned along guide bars 38 such that the pads 46 and48 underlie the joints of a specified truss. It will be noted that theonly connection between control assembly 53 and elevating assembly 54 isfluid line and that by unlocking control assembly 53 from hearing member91, the elevating apparatus is free for longitudinal movement with heelreaction pad 50 along guide bar 38. When heel reaction pad 50 isproperly positioned, control assembly 53 is located behind pad 50 alongmember 91, preferably in transverse alignment with one of the succeedingjoints for reasons as will become apparent. Control assembly 23 is thususually located about 8 feet behind pad 50, and is clamped in thisposition to member 91 and hence on jig table 36 behind leading reactionpad 50. The connector plates 18 are then spotted on the pads, ashereinbefore noted. The wooden members 30, 32 and 34 are arranged toform the truss 20, and the connector plates for the opposite side of thejoints are spotted along the truss.

The truss manufacturing apparatus is actuated, by means not shown, toadvance jig table 36, including the reaction pads, truss elements,connector plates, and the truss elevating apparatus hereof, throughpress 16 to successively locate the joints of the press 20 below pressplaten 52. Press 16 is actuated, by means not shown, to drive pressplaten 52 downwardly to embed the plates 18 on opposite sides of thewooden members into the joints formed thereby. It will be noted that theheight of the control and elevating assemblies 53 and 54 does not exceedthe combined height of the reaction pads and the truss members wherebyassemblies 53 and 54 may pass below the press platen 52 when the latteris in its lowermost position and are not affected thereby.

As the leading portions of the completed truss and the jig table emergefrom the exit side of the press 16, the leading heel portion of truss 20is elevated above heel reaction pad 50 as to overlie scoop plate 30 andfront roller 24. To this end, the distance between the scoop plate 30and the exit side of press 16 exceeds the distance between controlassembly 53 and the leading edge of truss 20, whereby control assembly53 is actuated to elevate the leading truss portion before the leadingedge of truss 20 passes below scoop plate 30. When control assembly 53underlies press platen 52 and the latter is displaced downwardly toembed connector plates 18 into a joint, press platen 52 engages roller84 causing linkage 72 and 78 to substantially straighten into the dashedline configuration of FIG. 6, whereby piston rod 68 is driven againstthe bias of spring 69 in a direction to displace fluid from cylinder 64.The displaced fluid communicates into slave cylinder 18 via line 90 toretract piston rod 122. Retraction of rod 122 pivots lever arm 128 aboutpin 104 with lever arm 128 engaging the underside of arm 106 to pivotlever 103 about pin 104. As seen by the dashed lines in FIG. 10, thispivoting action of lever 103 causes dowell 108 to bear against and slidealong the undersurface of the completed leading truss portion raisingthe latter from heel reaction pad 50 a distance such that the leadingedge of truss 20 is elevated above scoop plate 30. Continuousadvancement of jig table 36 along conveyor 12 brings truss 20 intooverlying relation with rollers 24 and 26, whereby truss 20 is strippedor peeled from successive reaction pads as it emerges from press 16.

Upon retraction of press platen 52, the springs 69 and 124 in cylinders64 and 118, respectively, extend their associated piston rods wherebyfluid communicates from slave cylinder 118 to master cylinder 64,returning fluid to the master cylinder for subsequent operation. Notethat the pin 80 is offset above a straight line drawn between pins 76and 86 when piston rod 68 is fully retracted. Accordingly, extension ofpiston rod 68 pivots linkage 72 and 78 to project roller 84 abovecontrol assembly 53 whereby the latter is ready for subsequentoperation. The extension of piston rod 122 by spring 12 pivots lever arm128 to its normal horizontal position. Lever 103, however, remains inthe inclined position illustrated by the dashed lines in FIG. 10 with astop 134 on a hinged portion of lever 103 precluding further clockwisepivotal movement from the dashed line position until arm 106 butts scoopplate 30, whereby arm 106 and lever 102 pivot back to the normalhorizontal position with arm 106 directly overlying lever arm 128.Accordingly, after truss 20 is displaced from jig table 36 intooverlying position on unloading rollers 24 and 2.6, the elevating deviceis automatically returned to its normal position ready for subsequentuse.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiment is therefore to be considered in all respects as illustrativeand not restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description, and allchanges which come within the meaning and range of equivalency of theclaims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States LettersPatent is:

1. Apparatus for elevating at least a portion of a wooden structureformed of wooden elements connected one to the other by connector platesembedded into the joints thereof comprising means for supporting thewooden elements, a member carried by said support means in underlyingrelation to at least one of the wooden elements and mounted for pivotalmovement, press means for embedding the connector plates into thejoints, a fluid actuated cylinder operably connected to said member forpivoting said member from a first position to a second positionelevating at least a portion of the structure above said structuremeans, and motor means spaced from said cylinder and operable inresponse to operation of said press means to actuate said cylinder andthereby pivot said member to said second position.

2. Apparatus according to claim 1 wherein said motor means comprises asecond cylinder in fluid communication with said first mentionedcylinder and means connected to said second cylinder and responsive tooperation of said press means to displace fluid from said secondcylinder to said first cylinder.

3. Apparatus according to claim 1 wherein said support means includes ajig table, said member and said cylinder being carried by said jigtable.

4. Apparatus according to claim 2 wherein said support means includes ajib table, said member and said cylinders being carried by said jigtable.

5. Apparatus according to claim 4 wherein said cyl inders and saidmember are mounted for longitudinal movement along said jig table, andmeans for clamping said cylinders and said member in adjustedlongitudinal position along said jig table.

6. Apparatus according to claim 4 wherein said second cylinderconnecting means includes a linkage carried by said jig table andprojecting above the jig table and the wooden elements carried thereby,said press means including a reciprocable press platen, said linkagebeing operable to actuate the second cylinder in response to downwardmovement of said press platen toward the wooden elements.

7. Apparatus according to claim 6 wherein said second cylinder includesa piston rod, said linkage including a pair of links pivoted one to theother, an end of one of said links being pivotally carried by said jigtable with the end of the other of said links pivotally connected tosaid piston rod, and a spring normally biasing said piston rod to aposition projecting the common pivoted joint of said links above saidjig table and the wooden elements.

8. Apparatus according to claim 5 including a heel reaction pad carriedby said jig table for longitudinal movement therealong, said memberbeing pivoted to said heel reaction pad and said first cylinder beingcarried by said heel reaction pad.

9. Apparatus according to claim 8 wherein said first cylinder has apiston rod, a lever arm connected to said piston rod and to said heelreaction pad, said lever arm underlying said member for joint pivotalmovement with said member in one direction and independent pivotalmovement in the other direction.

10. Apparatus according to claim 2 including an unloading assemblyhaving a roller extending transversely across and spaced above saidsupport means, said member elevating at least a portion of saidstructure onto said roller.

11. Apparatus for elevating a wooden structure formed of wooden elementsconnected one to the other by connector plates embedded into the jointsthereof by a press comprising means for supporting the wooden elementsincluding a jig table longitudinally movable along a predetermined pathleading to and through the press, a member carried by said support meansand mounted for movement between a first position and a second positionelevat ing the structure above the support means, a pair of cylinders influid communication one with the other, one of said cylinders beingcoupled to said member for moving said member from said first positionto said second position, the other of said cylinders being carried bysaid support means and longitudinally spaced from said first mentionedcylinder, said second cylinder being responsive to operation of thepress to provide fluid to said first cylinder thereby to elevate thestructure above said support means.

12. Apparatus according to claim 11 wherein said member and saidcylinders are carried by said jig table for movement therewith.

13. Apparatus according to claim 11 wherein at least one of saidcylinders is mounted for longitudinal movement along said support means,means for clamping said one cylinder to said support means in selectivelongitudinally spaced position from said other cylinder.

14. Apparatus according to claim 11 including linkage means connected tosaid other cylinder and projecting above said table and the woodenelements carried thereby, said linkage means being responsive tooperation of the press to displace fluid from said other cylinder tosaid first cylinder.

References Cited UNITED STATES PATENTS 3,212,694 10/1965 Sanford 2271523,431,619 3/1969 Bowers 29200 3,456,323 7/1969 Huyvaert et al. 29200THOMAS H. EAGER, Primary Examiner US. Cl. X.R. 227l52 22 33 UNITEDSTATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,538,578Dated November 10, 1970 RICHARD E. HEISE ET AL Inventor(s) pears in theabove-identified patent It is certified that error ap ected as shownbelow:

and that said Letters Patent are hereby corr r- Column 3, line 41,"2,877,523" should read 2,877,520 Column 4, line 48, "emerges" shouldread emerge line 68, delete "plate". Column line 42, "structure means"should read support means line 55, "jib" should read jig Signed andsealed this 20th day of April 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting OfficerCommissioner of Patents

